Google owns the smartphone space. With Android on nearly three out of every four smartphones sold during the third quarter, it has all but destroyed its competitors. The closest rival is Apple's iOS platform, which has a paltry 13.9% in comparison. The rest of the field? Fighting for Google and Apple's scraps.

Gartner estimates that Google sold 122.5 million Android devices in the July - September period, doubling the 60.5 million it sold during the same period a year ago. That's massive growth, and it shows no signs of abating. Google says it is activating 1.3 million new Android handsets each and every day.

Apple posted growth, too, boosting sales from 17.3 million iPhones a year ago to 23.6 million this year. But Apple actually lost market share, dropping from 15% to 13.9%.

Sales of BlackBerrys dropped from 12.7 million to 8.9 million, and RIM's market share collapsed from 11% to 5.3%. Bada, Samsung's proprietary smartphone platform (which most people have probably never even heard of), shipped 5 million units, giving it 3% of the smartphone market. That's more than Symbian and Windows Phone. Symbian plummeted from 16.9% a year ago to a meager 2.6% this year.

Meanwhile, Microsoft's Windows Phone platform improved from 1.7% a year ago to 2.4% this year, with sales of just 4 million units during the third quarter of this year.

Keep in mind, these are worldwide figures. In the U.S., the rankings are: Android, iOS, BlackBerry 7, and Windows Phone. But BlackBerry 7 and Windows Phone have such a small percentage of the market, they're almost not even in the game.

And that's the problem.

Google's Android platform has caught on like wildfire. Four years ago, it was a fledgling platform with one device -- a curiosity at best. Android and iOS together have destroyed the fortunes of Nokia and RIM. Nokia was the long-time top provider of smartphones, with RIM's BlackBerry behind it. Now, both companies are scrambling to survive. Android has successfully pushed the former market leaders face first into the dirt.

Competition is good, but Android and iOS together have formed a smartphone duopoly of sorts. Combined, they own about 85% of the industry. The market can't support more than three or four real platforms, but whichever platforms take those third and fourth spots need to do better than taking just 5% from Apple and Google.

Microsoft and RIM are both staging comebacks, but their potential for real success against these two juggernauts is uncertain. Windows Phone 8 is an excellent platform that deserves a spot on the pedestal with Android and iOS. We'll see just how competitive BlackBerry 10 is in a few months.

The ecosystem strategy is the best approach. Google and Apple have vast ecosystems supporting their platforms. Microsoft is in a better position than RIM in this regard, as its ecosystem is much larger and already present in many homes and businesses thanks to Windows and XBox. But is it enough? Can WP8 really take a significant (>10%) piece of Google's Android pie? Can RIM, with BB10?

I hope so.

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